Germination studies in Juncus acutus L. (Juncaceae), Schoenus nigricans L. (Cyperaceae) and Arthrocnemum macrostachyum (Moric.) Moris (Chenopodiaceae) for salt-marshes restorati

Abstract

Since the 1970’s, salt marshes have been reduced in area by a great antropogenic pressure derived from agriculture, and more recently, from demand for tourist urban facilities. Therefore, restoration and preservation of plant communities in salt marshes are needed. Among the perennial species that appear typically in maritime sands, on the Mediterranean region and western Europe Juncus acutus L. (Juncaceae), Schoenus nigricans L. (Cyperaceae) and Arthrocnemum macrostachyum (Moric.) Moris (Chenopodiaceae) frequently occur (Álvarez-Rogel et al., 2000; Vicente et al., 2007). On other hand soil salinity has traditionally been considered one of the most important physical factors in plant zonation of salt marshes (Fig.1). Álvarez-Rogel et al. (2006) related the increase in soil salinity in summer to a higher content in Cl−, Na+, SO42−, Ca2+, Mg2+ and K+. However, the relative percentages of Ca2+ and K+ decreased when salinity rose, leading to an imbalance in favour of the most toxic cations, such as Na+ and Mg2+. The same authors showed that the highest correlation coefficients for ions were between Cl− and Na+ and between Cl− and Mg2+. The use of the above mentioned species in restoration programs require to know the germination responses to light and temperature and their salinity tolerance during germination.